Browsing by Author "Hu, Xinyao"

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    Effect of microarc oxidation time on electrochemical behaviors of coated bio-compatible magnesium alloy
    (2014) Liu, Jiayang; Zhang, Wiejie; Zhang, Hanying; Hu, Xinyao; Zhang, Jing
    Magnesium alloys are newly promising biomaterials with potential application of human bone replacement. However, there is a drawback due to their high corrosion rates. In this study, AZ31 magnesium alloys were coated using microarc oxidation (MAO) process. Two oxidation durations, 1 minute and 5 minutes, were used. The samples were immersed in the simulated body fluid (SBF) for up to seven days. Then the electrochemical behaviors of the two samples were comparatively investigated. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) experiments were used. The results show that the 5-minute MAO coated sample had a better corrosion resistance than the 1-minute MAO coated sample. The study shows processing parameters, e.g., oxidation time, can be used to design an optimized MAO-coated magnesium alloy with controlled corrosion rates.
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    Electrochemical Characteristics of AZ31 Magnesium Alloys with Microarc Oxidation Coating
    (Office of the Vice Chancellor for Research, 2013-04-05) Berman, Alycia; Zhang, Weijie; Zhang, Hanying; Hu, Xinyao
    When considering implantable biomaterials, one possible solution that has arisen in recent years is the use of magnesium alloys due to their excellent mechanical properties. Magnesium alloys have many properties comparable to bone, including strength-to-weight ratio, density, and yield strength. For those reasons, magnesium alloys have been viewed as a promising biomaterial. Unfortunately, magnesium alloys are also prone to corrosion attack. To decrease the corrosion, studies have been taken to find appropriate coatings. One possibility is microarc oxidation (MAO) coating. However, studies have yet to be conducted to determine the corrosion of magnesium alloys with MAO coating. In this study, both MAO-coated and uncoated magnesium alloys will be placed in 0.9% saline solution and simulated body fluid and a time study will be conducted. The corrosion properties will be measured through use of a computer-generated Tafel curve, as well as through optical microscopy of the corrosion over the course of time.When considering implantable biomaterials, one possible solution that has arisen in recent years is the use of magnesium alloys due to their excellent mechanical properties. Magnesium alloys have many properties comparable to bone, including strength-to-weight ratio, density, and yield strength. For those reasons, magnesium alloys have been viewed as a promising biomaterial. Unfortunately, magnesium alloys are also prone to corrosion attack. To decrease the corrosion, studies have been taken to find appropriate coatings. One possibility is microarc oxidation (MAO) coating. However, studies have yet to be conducted to determine the corrosion of magnesium alloys with MAO coating. In this study, both MAO-coated and uncoated magnesium alloys will be placed in 0.9% saline solution and simulated body fluid and a time study will be conducted. The corrosion properties will be measured through use of a computer-generated Tafel curve, as well as through optical microscopy of the corrosion over the course of time.
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    STAT6-mediated keratitis and blepharitis: a novel murine model of ocular atopic dermatitis
    (Association for Research in Vision and Opthalmology, 2014-06) Turner, Matthew J.; DaSilva-Arnold, Sonia; Luo, Na; Hu, Xinyao; West, Callah C.; Sun, Lou; Hall, Christopher; Bradish, Joshua; Kaplan, Mark H.; Travers, Jeffrey B.; Sun, Yang; Department of Ophthalmology, IU School of Medicine
    PURPOSE: Atopic dermatitis (AD) is a common inflammatory disease that can affect the eye, resulting in ocular pathologies, including blepharitis, keratitis, and uveitis; however, the pathogenic mechanisms underlying the ocular manifestations of AD are not well understood. METHODS: In the present study, we characterized the ocular pathologies that develop in the Stat6VT mouse model of AD. We examined the cytokine profile of the eyelid lesions, measured the behavioral response, and documented the treatment response to topical steroids. RESULTS: Our results show that Stat6VT mice spontaneously developed blepharitis, keratitis, and uveitis similar to that observed in patients with AD. Histologic findings of allergic inflammation in affected eyelids in this model include the presence of a lymphocyte-predominant infiltrate and tissue eosinophilia in the dermis. Gene expression analysis of affected eyelid tissue by quantitative PCR revealed increased amounts of mRNAs for the Th2 cytokines IL-4, IL-5, and IL-13. In addition, increased eyelid scratching was seen in Stat6VT mice with blepharitis. Topical treatment with the corticosteroid clobetasol reduced eyelid inflammation, tissue eosinophilia, and Th2 cytokine expression. CONCLUSIONS: The development of AD-like ocular pathologies in this model supports the idea that in humans, AD-associated disease of the eye may be driven by Th2-mediated inflammation and demonstrates that the Stat6VT mouse may be a useful system in which to further investigate pathogenesis of and treatment strategies for blepharitis and other ocular diseases that develop in association with AD.